Dee Estuary Birding
Monthly Newsletter...
October 2025
Newsletter
The Glossy Ibis Invasion
Adrian Langdon - http://www.images-naturally.co.uk/
When 30 Glossy Ibis flew south over Formby Point and
Crosby sand dunes
and then landed in the middle of the Dee Estuary between Parkgate and
Flint on September 5th (2025), it was the biggest flock ever recorded
in this country. That proud record lasted just one day as it soon
became
obvious that an unprecedented influx was taking place across the UK,
records were broken every day and on September 8th the largest flock
was 92 in Cornwall, with a staggering minimum of 605 Glossy Ibis in the
country that day (Ref 1). Good numbers remained for the rest of the
month with Chew Valley Lake having a large flock for several days
including 72 on the 19th, 22 were at Horsey Mill, Norfolk, on the 21st
and in southern Ireland 34 were near Cork on the same date, many other
double-figure flocks were recorded. By the month-end most large flocks
had dispersed although records of single birds were widespread -
notable records were seven on the island of Unst and and 14 were still
near Cork, both on the 29th.
to the Dee Estuary. This was taken as they flew low through Formby sand dunes - I have no idea why they were flying so low!
© Steven Cross
Where did all these Glossy Ibis come from? I shall go into more detail about the history of the Glossy Ibis in western Europe, the UK and on the Dee estuary below, but in early 2025 something interesting was happening in Donana National Park in south-west Spain with heavy and prolonged rain in March. It was among the wettest springs on record resulting in most of the Donana National Park being covered in water (Ref 2). This was heaven for Glossy Ibises! The result was a massive 12,300 pairs breeding and we hear they had a very productive season (Ref 3).
Although
the influx into the country in early September was unprecedented it
was, perhaps, not totally unexpected given the phenomenally good breeding
season in Donana, and we know there is a strong connection between
Donana National Park and the UK as 87% of all ringed birds found in
this country have come from there (Ref 4). The young of this species is
known for it's wide post-breeding dispersal, often in large flocks, and
the timing of this dispersal this year coincided with some strong
southerly winds which could well be the reason for the large numbers
invading the UK.
To put this influx into perspective here is a bit of history into the fortunes of the Glossy Ibis in western Europe, the UK and the Dee Estuary.
Glossy Ibis in western Europe
The above graphic (courtesy of ChatGPT) nicely sums up the status of
Glossy Ibis across Europe over the past couple of centuries, showing
the
severe decline, almost to extinction, followed by an amazingly rapid
recovery since the turn of the current century.
Historically, their main breeding area was south-east Europe (Ref 5)
but this recent dramatic increase has taken place mainly in the Iberian
peninsula, along with the Carmargue in southern France. In recent years
the Donana
National Park usually has more
pairs breeding than any other site although numbers are very variable
with few breeding in dry years. There were just seven pairs in 1996,
this had increased to more than one
thousand in 2004 and then to more than ten thousand in
2017 (Ref 6). On the north-east coast of Spain numbers have not been
quite as
high but the increase has been just as dramatic as demonstrated in the
two graphs below (Ref 7):
Similar graphs could be drawn for wetlands in Portugal (e.g. the Tagus estuary) and the Carmargue in France. BWP (Ref 5), written before this increase, says that "post-fledgeling dispersals merge into autumn migration as adults and young withdraw south of breeding range in Europe". This migration to Africa probably still occurs in eastern Europe and into Asia but, as the above graph demonstrates, nearly all the Glossy Ibises in western Europe seem to stay put.
Many of these birds feed on rice fields, but they are not eating rice but rather various invertebrates. These incudes invasive species such as the Apple Snail and both Red Swamp and Signal Crayfish which have devastated the native crayfish species - so they are doing a great job controlling these pest species (Ref 8).
Glossy Ibis in the United Kingdom
There were 340 accepted records in the UK prior to 1950 (Ref 9) but
between then and 2006 Glossy Ibis were barely annual in this country,
no doubt reflecting their decline in Europe over that period. The bar
chart clearly shows the increase in the number of birds recorded from
2007, and in 2013 the BBRC no longer classed Glossy Ibis as a
nationally rare
bird. It was then reported in British Birds in the annual 'Report on
scarce migrant birds in Britain' until 2022 since when there were too
many birds being reported to even qualify for that report. Even so,
most records have been of ones and twos with very few flocks getting
into double figures. 17 at Slimbridge in April 2007 was exceptional for
that year, and in 2019 and 2020 there were three flocks of over 20
birds the largest being 28 at Marloes Mere in Pembrokeshire in November
2020. Nearer to home seven birds were on Neumann's Flash, Cheshire, in
May 2007.
Glossy Ibises have only successfully bred once in this country, that was at RSPB Frampton Marsh in 2023. But expert opinion (Ref 9) suggests that they will probably become regular breeders in the near future but only in small numbers as we just don't have the large wetlands required by this species, perhaps with the exception of Avalon Marshes in Somerset.
Glossy Ibis on the Dee Estuary
The first record was in 1959, and Glossy Ibis
remained an exceptionally rare bird for the rest of the 20th century
with just one other record. In line with the increase in Europe they
have been recorded more frequently since 2007 but it still remains a
rare bird here on the Dee Estuary. Here is the full list of records up
to the end of September 2025 (Ref 10, 11, 12), note that they are all
of single birds except for the flock of 30 on Sep 5th and four at Parkgate on Sep 30th:
References
Several of the articles referenced below were in a
single publication: SIS Conservation, Issue 1: Special Issue Glossy
Ibis Ecology & Conservation. You can download the PDF here
https://storkibisspoonbill.org/publications/sis-conservation-issue-1-special-glossy-ibis/
1. Josh Jones, Massive Glossy Ibis arrival reaches Britain and Ireland, BirdGuides, 9th September 2025.
2. Jose Luis Piedra, Donana National Park in Spain
is resurrected by the latest rains, SUR in English
(https://www.surinenglish.com),
1st April 2025.
3. Spanish Ornithological Society, Donana Rivive, SEO Bird Life, 2nd July 2025 - To read the article (in Spanish) Click Here.
4. Online Ringing and Nest Recording Report, BTO - Click Here.
5. Birds of the Western Palearctic - App Edition, Nature Guides.
6. Manuel Manez et al., Twenty Two Years of Monitoring of the Glossy Ibis in Donana, SIS Conservation 1 (2019) 98 - 103.
7. Antoni Curco Masip et al., Status of Glossy Ibis in the Ebro Delta (Catalonia), SIS Conservation 1 (2019) 104 - 109.
8. Albert Bertolero, A native bird as a predator for the invasive apple snail, a novel rice field invader in Europe, Aquatic Conservation, Volume 28 (5), Oct 2018.
9. Malcolm Ausden et al., The Changing Status of the Glossy Ibis in Britain, SIS Conservation 1 (2019) 116 - 121.
10. Allan Conlin & Eddie Williams, Rare and Scarce Birds of Cheshire & Wirral, 2017.
11. Robin Sandham, Scarce and Rare Birds in NorthWales, 2017.
12. Dee Estuary Birding, http://www.deeestuary.co.uk/.
Richard Smith
Colour Ring Report
A busy month for colour ring spotting, below are some of the highlights.
Hobby
Green (19)
Ringed at Broughton, Flintshire, on a farm near the A55 in August 2024.
Recorded at Burton Mere Wetlands on 05/09/2025.
This the first colour ringed Hobby in our database.
Ringed Plover
Y - GWO
Ringed on passage at Pontevedra, NW Spain, 06/09/2023.
Recorded at Meols Shore on 30/08/2025. No other records.
Curlew
O - GY(7H)
Ringed at Llanrhystud, just south of Aberystwyth, on 30/10/2023, as an
adult male.
Recorded on Heswall Fields on 16/09/2025.
Redshanks
YfG-GY.
Ringed at Laugarvatn, SW Iceland (about 50km east of Reykjavik), on
21/05/2025, as breeding adult.
Recorded at Heswall and Thurstaston Shore four times in September 2025.
This is a new scheme by the Icelandic ringers, and the first foreign ringed Redshank in our database.
It's always good to get feedback directly from the
ringer and this is what Guoni Sighvatsson said:
"It had a quite a remarkable summer as it nested between a newly built
house and the local swimming pool. During the summer when the grass was
cut the lawnmower went over the nest a few times but still the eggs
hatched and i metal ringed all four chicks when they had moved closer
to the shore."
We saw three Redshanks ringed by the Mid-Wales
Ringing Group in September, and, in total, 15 of the 29 Redshanks in
our database have been ringed by them. There's no particular reason why
there should be such a strong connection between the two sites, so I
guess it just reflects the huge amount of ringing effort this group
puts in
- we also see Dunlins, Knots, Curlews and other species ringed by them.
Black (PV)
Ringed at Ynyslas on 02/08/2019 as a juvenile.
Recorded on Heswall Shore on 06/09/2025. No other records.
Black (HW)
Ringed at Ynyslas on 24/01/2019.
Recorded on Heswall Shore in August 2022, August 2023 and September
2025.
Black (AEP)
Ringed at Ynyslas on 25/01/2020 as a 2cy bird.
Recorded on Oakenholt Marsh in August 2022, and on Heswall Shore
September 2024 and 2025.
Shelduck
Blue (JN)
Ringed at WWT Martin Mere on 15/06/2021 as a breeding female.
This bird is known to have bred at Martin Mere in 2021 and 2022, and
spends most of each winter there being recorded many times
including last winter, 2024/25, when it was recorded 23 times!
It was at West Kirby in September 2022, at Thurstaston in September
2023 and at Meols on 21/09/2025. This bird is the only colour-ringed
Shelduck which we have seen at all our three main Shelduck colour ring
spotting sites - Meols, Thurstaston and West Kirby.
In 2021 JN was seen with 10 tiny ducklings in
the grounds of Martin Mere. When ringed (in a nest box) she was
temporarily fitted with a satellite tag and they were able to track her
making two trips to the Ribble Estuary in July 2021 before she shed the
tag.
Lesser Black-backed Gull
Yellow (5B:W)
Ringed on Walney Island in June 2016 as a breeding adult (i.e. at least
4 years old).
It's been seen at Hoylake in September 2017, October 2020, September
2022 and September 2025.
Black-headed Gull
White (TMEN)
Ringed near Lodz (west of Warsaw), Poland, on April 2013 as an adult.
This is our most recorded gull being seen at least 78 times around the
Dee Estuary and North Wirral every year since being ringed. We always
look forward to it returning here after breeding, it was late this year
as our first record wasn't until September 15th, on West Kirby Shore,
in 2024 it turned up in July. As far as we know it breeds every year in
Poland, probably on the Vistula River near Wloclawek, west of Warsaw,
where it's been recorded three times, including June 2025.
Colour Rings were recorded by Richard
Smith, Stephen
Hinde, Richard Speechley, Alan Hitchmough, Sean
O'Hara, Tony Ormond, Graham Connolly, Mike Pollard, Steve Williams,
Andrea Sawiak, David King, Jeff
Hodgson, Charles Farnell, Steve Round, Paul Ralston and Angela Graham.
Richard Smith
September Bird News
September 16th © Pete Sutton
September 16th was a classic September birding
day with a westerly gale which blew in plenty of sea birds. We had
Leach's Petrels flying along north Wirral and Hilbre all day with the
two highest counts being 19 at Hoylake and 34 at Hilbre. Other good
birds were a Pomarine Skua and 14 Arctic Skuas past Hilbre, and two
Great Skuas and three Sabine's Gulls counted from Hoylake. Two Grey
Phalaropes were off Leasowe Lighthouse, and there were several records
of single Grey Phalaropes (maybe the same bird) for the rest of the
month, at Point of Ayr and along north Wirral.
There was a big influx of Curlew Sandpipers into the
country and we had our share - the three highest counts were 14 at
Hoylake on the 11th with 22 there on the 13th, and 16 at Heswall on the
20th. Ruff numbers remained high at Burton Mere Wetlands with 30 0n the
4th.
24 Spoonbill at Parkgate on the 19th was a
record high count for the Dee estuary and at least 25 Great White
Egrets on Burton Marsh on the 13th was a nice high count, as was 5,930
Black-tailed Godwits at Caldy. The good passage of Greenshanks
continued and included 23 at Heswall on the 21st, a very good count for
that site. Towards the end of the month 275 Great Crested Grebes and
3,000 Common Scoters were on a flat calm sea off Hoylake on the 29th.
Rare birds include the Glossy Ibises featured in the above article, and we also had a Nightjar (23rd) and a Yellow-browed Warbler (26th) on Hilbre. Last, but not least, was a Slavonian Grebe showing really well on West Kirby Marine Lake over the last four days of the month, as the photos demonstrate.
What to expect in October
North-west/Westerly gales, especially early in the month, should result
in some good sea-watching with Leach's Petrels, Skuas, Sabine's Gulls
etc.
October can often bring in some good rarities, and
one we see most years are Yellow-browed Warblers which have travelled
all the way from Asia. Given the right weather conditions, a light to
moderate south-east wind with some cloud cover, we can get large
movements of finches and thrushes moving south along the coast. In 2022
we had a massive and spectacular Redwing migration through here in
October - read the article in the December
2022 Newsletter.
Shelduck numbers usually peak this month and we can expect between 5,000 and 10,000 on Dawpool Bank off Thurstaston. We can also expect an influx of Cattle Egrets into Burton Mere Wetlands, we had 34 last year.
Hen Harriers and Short-eared Owls will return to the marshes and watch out for Marsh Harriers flying into their roost in Neston Reedbed, could well be over 20.
There will be a noticeable increase in Knots and
Dunlins arriving for the winter, and the spring tides should result in
some spectacular high tide roosts at Hoylake and Point of Ayr.
October Highest
Tides:
7th 11.51hrs (BST) 9.7m
8th 12.29hrs (BST) 9.8m
9th 13.09hrs (BST) 9.8m